Condition category
Mental and Behavioural Disorders
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
The relationship between tobacco and cannabis use is multi-layered, but current cessation programs usually focus on one substance while addressing the other substance marginally or not at all. Therefore we developed the first integrative group cessation program for co-smokers of cigarettes and cannabis that will be tested for feasibility (acceptance, safety, etc) and effectiveness (e. g. how many participants succeed in abstaining from cannabis and tobacco during the program and in the longer term).

Who can participate?
Co-smokers of tobacco and cannabis can take part that have a minimal age of 18, either sex, smoke at least five cigarettes per day in the past 30 days to study entry, and who at least once a week used cannabis in the past 30 days prior to study entry.

What does the study involve?
In this program, all participants can learn the same program to abstain from tobacco and cannabis use facilitated by specifically trained psychologists and psychiatrists within 2 months.

What are the possible benefits and risks of participating?
Co-abstinence of tobacco and cannabis is difficult to reach by oneself without professional help. Therefore participants receive professional help in groups of 8 to 12. Tobacco and cannabis abstinence may cause withdrawal symptoms or adverse events. In case of serious withdrawal symptoms or adverse events, additional therapy is provided.

Where is the study run from?
The study is lead by the Swiss Research Institute for Public Health and Addiction, an associated institute to Zurich University and a World Health Organization (WHO) collaborating center for substance abuse.

When is the study starting and how long is it expected to run for?
The study started in February 2012 and will run until April 2013. Participants will be recruited within this time period.

Who is funding the study?
The study is funded by the Swiss Tobacco Prevention Fund.

Who is the main contact?
Ms Julia Becker, Scientific Employee

Trial website

Contact information



Primary contact

Dr Michael Schaub


Contact details

Swiss Research Institute for Public Health and Addiction ISGF
Konradstrasse 32
P. O. Box
+41 44 448 11 60

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Feasibility study of a Integrative Smoking Cessation Group Program for adult co-smokers of cigarettes and cannabis



Study hypothesis

The relationship between tobacco and cannabis use is multi-layered, but current national and international cessation programs usually focus on one substance while addressing the other substance marginally or not at all. This study investigates the feasibility and preliminary efficacy of an integrative smoking cessation program for adult co-smokers of cigarettes and cannabis.

Ethics approval

Ethics Committee of the Canton of Zurich, Switzerland, 27/06/2011, ref: KEK-StV-Nr. 23/11

Study design

Interventional feasibility study
Cross sectional clinical cohort study

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Nicotine dependence and cannabis misuse/abuse


The study is taking place in two different addiction outpatient treatment sites.

The course is structured into six weekly sessions and one revival meeting about six weeks after the last session. Each of the sessions lasts between 90 and 120 minutes. Additionally, the course facilitators offer every participant one individual counselling session on request.

Subsidiary elements of the course sessions are a smoking diary and a workbook, which are introduced and distributed to the participants in the first session. The workbook contains background information, an overview of the course structure and contents, and work sheets to reflect on personal reasons for cessation and to develop and write down personal strategies. The smoking diary is a small notebook which can be easily carried to constantly monitor consumption, but also thoughts, feelings and actions associated with the use of one or both of the substances. Participants measure their expired carbon monoxide at every session to gain an objective feedback on their therapy progress and for later program evaluation. They can enter their individual values in their notebook and thus monitor the changes in the values.

The main goal of the intervention is dual abstinence of tobacco and cannabis. Carbon monoxide is assessed at every session. Further applied outcome measures are assessed at baseline, the last therapy session and at 6 months follow-up.

Intervention type



Not Applicable

Drug names

Primary outcome measures

Frequency of tobacco and cannabis use in the last 7 days. Saliva samples are collected to assess cotinine levels at baseline, at the end of treatment, and at 6 months after the quit date for the biological validation of tobacco use.

Secondary outcome measures

1. Severity of nicotine and problematic cannabis use
2. Smoking attitudes
3. Depression (Beck Depression Inventory)
4. Anxiety measures (Beck Anxiety Inventory)
5. Cannabis and tobacco craving
6. Smoking cessation symptoms
7. A general health measure (SF12)
8. Smoking abstinence self-efficacy
9. Motivation to quit (according to the health action process approach for each and both substances together)
10. Other psychoactive substance use.
Moreover we will assess diverse course evaluation measures with the participants at the last session of their course. The course will be evaluated also in view of the course facilitators after the study intervention phase.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Minimal age 18, either sex
2. Smoking at least five cigarettes per day in the past 30 days prior to study entry
3. At least once a week cannabis use in the past 30 days prior to study entry

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Current serious psychiatric illness or history of psychosis, schizophrenia, bipolar type I disorder or significant current suicidal or homicidal thoughts
2. Use of bupropion or nicotine replacement therapy (NRT) or other smoking cessation treatment at study entry
3. Current behavioral treatments for cessation of marijuana or tobacco smoking
4. Inability to read or write in German

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Swiss Research Institute for Public Health and Addiction ISGF

Sponsor information


Swiss Tobacco Prevention Fund (Switzerland)

Sponsor details

Federal Office of Public Health FOPH
Hessstrasse 27E

Sponsor type




Funder type


Funder name

Swiss Tobacco Prevention Fund (Switzerland) grant number 09.008182

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2013 results in:

Publication citations

  1. Results

    Becker J, Hungerbuehler I, Berg O, Szamrovicz M, Haubensack A, Kormann A, Schaub MP, Development of an integrative cessation program for co-smokers of cigarettes and cannabis: demand analysis, program description, and acceptability., Subst Abuse Treat Prev Policy, 2013, 8, 33, doi: 10.1186/1747-597X-8-33.

Additional files

Editorial Notes